Hello,

 I have a table where I want to insert values for each day and each ID:

Table: Availabilities

HotelID (bigint)

Day (datetime)

Availability (smallint)

to ensure that a hotel can only have one Availability Value for each day (e.g. 2008-06-10 00:00:00) I see two solutions:

HotelID and Day as combined primary key or HotelID and Day as unique constrained. Note that a SP will ensure that only datetimes with time 00:00:00 can be inserted.

How would you solve this?

greetings

Wow, you must have really many hotels if you need to use a bigint as data type for HotelID!

Without knowing the full specification here, I would tend to have a composite PRIMARY KEY here. A UNIQUE constraint would essentially achieve the same, with the exception that the constraint would accept NULL markers which wouldn't be what you want here, right?